A battery stores and releases energy by electrochemical reaction(s) at the surfaces of its electrodes. Each cell of a lead-acid battery in the fully charged state contains electrodes of elemental lead (Pb) and lead (IV) dioxide (PbO2) in an electrolyte of dilute sulfuric acid (H2SO4). In the discharged state both electrodes turn into lead(II) sulfate (PbSO4) and the electrolyte loses its dissolved sulfuric acid and becomes primarily water. In the pasted-plate construction each plate consists of a lead grid initially filled with a paste comprising a mixture of leady oxide (Pb and PbO) and dilute sulfuric acid. This construction allows the acid in the paste to react with the leady oxide inside the plate during cell formation (first charge and discharge cycle during which linkages between neighbouring particles, increasing the electrical conductivity and active surface area and thus the battery capacity. The paste may also contain carbon black, blanc fixe (fine barium sulfate), and lignosulfonate. The blanc fixe acts as a seed crystal for the lead to lead sulfate reaction. The lignosulfonate prevents the negative plate from forming a solid mass of lead sulfate during discharge. Carbon black counteracts the effect of inhibiting formation caused by the lignosulfonates.